package com._9xcloud.leaverequest.service;

import com._9xcloud.leaverequest.domain.Lesson;

import java.util.Set;

/**
 * Created by Administrator on 2015/5/28.
 */
public interface LessonService {
    Lesson getById(int lessonId);

    Set<Lesson> getByCourseId(int courseId);

    void removeAll();
}
